Input lag test

Delay in games and general movement on the screen can be a pain and in a common tongue this phenomenon is called input lag. It occurs if the electronics of the display introduces a small delay in the information received from its input (such as your graphics card). In games the result is most often the feel of losing control of whatever you should be controlling in the game.

There is no real software method of evaluating input lag and it cannot be read from the specifications of the display. You have to have the display in front of you and try it out for yourself. Most often you can do nothing to eliminate the problem either.

We have made a small program that is essentially just an on-screen counter. The test requires a lot of accessory that most users do not have, such as a monitor with minimum input lag (such as a CRT monitor) and a quick camera. Hence this tool might not be of use to everybody, but if you want to give a go, here are the prerequisites:

A graphics card with two outputs

Two screens connected to these outputs - one preferably a CRT monitor

A camera with high shutter speed (most digital cameras suffice)

The procedure is as follows:

Set your two monitors in clone mode

Run either the program or open the html document

Start the timer

Take a picture with your camera with both monitors i focus

If the input response is different on the two monitors, the number on each screen will be different